Signaling activities of amelogenin gene splice products.

牙釉蛋白基因剪接产物的信号传导活性。

• 批准号: 6858645
• 负责人: ARTHUR VEIS
• 金额: $ 28.81万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6858645
• 关键词: amelogenin; antibody; biological signal transduction; cell growth regulation; cementum; dental development; dentin; dentinogenesis; genetic regulation; immunocytochemistry; in situ hybridization; laboratory mouse; laboratory rat; mesenchyme; messenger RNA; microarray technology; neural crest; odontoblasts; phenotype; protein structure function; recombinant proteins; transcription factor

DESCRIPTION (provided by applicant): This is a revised application to study the potential of amelogenin pre-mRNA splice products to participate in epithelial-mesenchymal signaling during tooth morphoigenesis. Specific amelogenin mRNA splice products have been shown to have BMP-like activities leading to cartilage/bone induction when implanted into ectopic sites in vivo, and to induce expression of cartilage/bone phenotypic molecules in mesenchymal cells in culture. We have shown that two specific splice products, 73 and 59 amino acids in length, respectively, act by regulating the expression of transcription factors. They have different inductive effects on the development of tooth germs in culture. They also yield different effects on the repair of dentin defects and pulp mineralization. Although the amelogenin genes have been thought to be expressed only in the dental epithelium, amelogenin gene products have been shown to be present in the mantle dentin and we have evidence from in situ hybridization that they may be produced directly in early pre-odontoblasts. Others have shown that amelogenins may be involved in induction of tooth cementum. On the basis of these data we have hypothesized that the amelogenin gene small splice product peptides are transcriptional regulating factors that have a role in the epithelial-mesenchymal signaling that is such a prominent part of tooth development. Three specific aims are proposed for this study: 1) To use in situ hybridization to confirm the presence of amelogenin mRNAs in odontoblasts, and immunohistochemistry to determine the tooth developmental stages at which odontoblasts express the amelogenin gene message, and show the appearance of the peptide products in the odontoblasts; 2)To clarify in detail, using gene arrays and other techniques the effects of the peptides on directing the expression of odontoblast and cementoblast phenotypes during tooth development, in culture; and 3) To more completely determine the mechanisms by which the peptides interact with mesenchymal cells in general to alter their phenotypic expression. Logical extensions of these studies would be to examine, under Aim 2, the use of the peptides in more general heterotypic epithelial-mesenchymal recombination experiments, and, under Aim 3) to analyze the combined effects of the two peptides on the BMP-like activity on the phenotypic expression in mesenchymal cells in bone induction and tooth development. In this revision, more experimental details have been provided.

描述（由申请人提供）：这是一项修订后的申请，用于研究牙釉蛋白前体 mRNA 剪接产物参与牙齿形态发生过程中上皮间质信号传导的潜力。特定的牙釉蛋白 mRNA 剪接产物已被证明具有 BMP 样活性，当植入体内异位位点时可诱导软骨/骨诱导，并诱导培养的间充质细胞中软骨/骨表型分子的表达。我们已经证明，两种特定的剪接产物（长度分别为 73 和 59 个氨基酸）通过调节转录因子的表达发挥作用。它们对培养物中牙胚的发育有不同的诱导作用。它们对牙本质缺损的修复和牙髓矿化也产生不同的效果。虽然牙釉蛋白基因被认为仅在牙上皮中表达，但牙釉蛋白基因产物已被证明存在于地幔牙本质中，并且我们从原位杂交中获得证据表明它们可能直接在早期前成牙本质细胞中产生。其他研究表明牙釉蛋白可能参与牙骨质的诱导。根据这些数据，我们假设牙釉蛋白基因小剪接产物肽是转录调节因子，在上皮-间质信号传导中发挥作用，而上皮-间质信号传导是牙齿发育的重要部分。本研究提出了三个具体目标：1）利用原位杂交来确认成牙本质细胞中牙釉蛋白mRNA的存在，并利用免疫组织化学来确定成牙本质细胞表达牙釉蛋白基因信息的牙齿发育阶段，并显示成牙本质细胞中肽产物的出现； 2)使用基因阵列和其他技术详细阐明肽在培养物中牙齿发育过程中指导成牙本质细胞和成牙骨质细胞表型表达的作用； 3) 更全面地确定肽与间充质细胞相互作用以改变其表型表达的机制。这些研究的逻辑扩展将是在目标 2 下检查这些肽在更一般的异型上皮间质重组实验中的使用，并在目标 3 下分析两种肽对骨诱导和牙齿发育中间充质细胞表型表达的 BMP 样活性的组合影响。在这次修订中，提供了更多的实验细节。